Lipidation of the LC3/GABARAP family of autophagy proteins relies on a membrane-curvature-sensing domain in Atg3.

ABSTRACT: The components supporting autophagosome growth on the cup-like isolation membrane are likely to be different from those found on closed and maturing autophagosomes. The highly curved rim of the cup may serve as a functionally required surface for transiently associated components of the early acting autophagic machinery. Here we demonstrate that the E2-like enzyme, Atg3, facilitates LC3/GABARAP lipidation only on membranes exhibiting local lipid-packing defects. This activity requires an amino-terminal amphipathic helix similar to motifs found on proteins targeting highly curved intracellular membranes. By tuning the hydrophobicity of this motif, we can promote or inhibit lipidation in vitro and in rescue experiments in Atg3-knockout cells, implying a physiologic role for this stress detec

SUBMITTER: Nath S 

PROVIDER: S-EPMC4111135 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature